At the present time there are three main methods of irrigation which are in common use. The oldest and best known method of irrigation is so called "flood" irrigation wherein relatively large quantities of water are flooded onto the ground adjacent plants, the water soaking into the ground but carrying with it many salts, some of which are harmful.
A second type of irrigation which is commonly used is spray irrigation, and although this uses less water and therefore causes less salt damage, the spray irrigation system is subject to large evaporation loss, and in some instances the spray droplets can damage foliage.
To reduce the damage to foliage and to more effectively direct irrigating water, use has been made of drip irrigation systems. However, a build up of algae and solidification of minerals sometimes causes drop emitters to be blocked and can also cause a change in the pH balance of the irrigating water. Other particles can also cause blockage of drip emitters, and for that reason filters are often deemed necessary. Even with the use of filters however, drip emitters need to frequently be cleaned or adjusted or changed. Another difficulty with drip emitters is that they emit such small quantities of water that considerable time is taken to effect an irrigation cycle. A still further problem is that the water distribution pipes are usually located above the ground and liable to damage and deterioration.
The object of this invention is to provide a novel method of irrigating, a novel irrigation system, novel irrigation means and a novel strainer box which can be used in the system, wherein some at least of the above-mentioned difficulties are obviated.